temp 3.5

• What is tidal volume?

  The volume of air breathed at rest
• How is breathing rate calculated?

  By counting peaks or troughs in a minute
• What is residual volume?

  The air always present in the lungs
• What happens to tidal volume during exercise?

  It can be exceeded by inspiratory reserve volume
• What is expiratory reserve volume?

  The additional air exhaled beyond tidal volume
• What is digestion and absorption?

  • Digestion: Hydrolysis of large molecules
  • Absorption: Smaller molecules cross cell membranes
• What enzymes digest carbohydrates?

  Amylases, maltases, sucrases, lactases
• How are lipids digested?

  By lipases hydrolyzing ester bonds
• What role do bile salts play in lipid digestion?

  They emulsify lipids to increase surface area
• What are the three groups of peptidases?

  Endopeptidases, exopeptidases, dipeptidases
• How are amino acids absorbed in the ileum?

  By facilitated diffusion and co-transport with Na+
• What happens to monoglycerides and fatty acids after absorption?

  They reform into triglycerides in the ER
• What are the structures and functions of the mammalian gaseous exchange system?

  • Cartilage: Supports trachea and bronchi
  • Ciliated epithelium: Moves mucus to throat
  • Goblet cells: Secrete mucus to trap pathogens
  • Smooth muscle: Controls airway diameter
  • Elastic fibres: Control airflow during breathing
• What is ventilation?

  The flow of air in and out of alveoli
• What muscles are involved in inspiration?

  External intercostal muscles and diaphragm
• What occurs during expiration?

  Internal intercostal muscles contract, diaphragm relaxes
• What is a spirometer used for?

  To measure lung volume
• What is vital capacity?

  The maximum air volume inhaled or exhaled
• How are plants adapted for gas exchange?

  • Stomata: Allow gas entry and exit
  • Air spaces: Facilitate gas movement
  • Close proximity to mesophyll cells: Reduces diffusion distance
• What are the lungs?

  Lobed structures for gas exchange
• What protects the lungs during inflation and deflation?

  A lubricating substance prevents friction
• How does air enter the lungs?

  Through the nose, trachea, bronchi, bronchioles
• What is the role of cartilage in the airways?

  To keep airways open
• How do trachea and bronchi differ?

  Bronchi are narrower than trachea
• What is the structure of bronchioles?

  Narrower than bronchi, mostly smooth muscle
• What adaptations do alveoli have for gas exchange?

  • Very thin walls (one cell thick)
  • Surrounded by capillaries (one cell thick)
  • Large number (~300 million) for increased surface area
• Why do multicellular organisms need specialized exchange surfaces?

  To efficiently exchange gases due to size
• What features characterize an efficient exchange surface?

  • Large surface area
  • Thin structure
  • Good blood supply/ventilation
• How do fish maintain gas exchange?

  Through gills with counter current flow
• What is the function of gill filaments?

  To facilitate gas exchange in fish
• How does ventilation occur in fish?

  By opening mouth and lowering buccal cavity
• How do terrestrial insects transport oxygen?

  Through spiracles and tracheal tubes
• How do plants transport nutrients?

  • Xylem: Transports water and minerals (passive)
  • Phloem: Transports sugars (active)

  
• What is the structure of the vascular bundle in roots?

  • Xylem and phloem for transport and support
  • Xylem arranged in X shape for strength
  • Surrounded by endodermis and pericycle
• What is the structure of the vascular bundle in stems?

  • Xylem inside for support and flexibility
  • Phloem outside for nutrient transport
  • Cambium layer for new tissue production
• What is the structure of the vascular bundle in leaves?

  • Forms midrib and veins
  • Supports leaf structure and transport
• What are the components of the vascular bundle in roots?

  Xylem and phloem
• What is the function of xylem and phloem in plants?

  Transport substances and provide structural support

  
• How are xylem vessels arranged in the vascular bundle?

  In an X shape
• Why is the X shape arrangement of xylem vessels important?

  It helps withstand mechanical forces